functionized

R/05.R

@@ -63,37 +63,24 @@ library(tidyverse)
 
 input <- readLines("../input/05-01.txt")
 
-strsplit(input, "") %>%
-  map_dbl(~{
-
-    rng <- c(0, 127)
+partition <- function(seq, lb, ub, trigger) {
 
-    for (part in .x[1:7]) {
-      amt <- floor((rng[2] - rng[1])/2) + 1
-      if (part == "F") {
-        rng[2] <- rng[2] - amt
-      } else {
-        rng[1] <- rng[1] + amt
-      }
+  for (part in seq) {
+    amt <- floor((ub - lb)/2) + 1
+    if (part == trigger) {
+      ub <- ub - amt
+    } else {
+      lb <- lb + amt
     }
+  }
 
-    row <- if (.x[7] == "F") rng[1] else rng[2]
+  return(if (tail(seq, 1) == trigger) ub else lb)
 
-    rng <- c(0, 7)
-
-    for (part in .x[7:10]) {
-      amt <- floor((rng[2] - rng[1])/2) + 1
-      if (part == "L") {
-        rng[2] <- rng[2] - amt
-      } else {
-        rng[1] <- rng[1] + amt
-      }
-    }
-
-    seat <- if (.x[10] == "R") rng[1] else rng[2]
-
-    (row * 8) + seat
+}
 
+strsplit(input, "") %>%
+  map_dbl(~{
+    (partition(.x[1:7], 0, 127, "F") * 8) + partition(.x[8:10], 0, 7, "L")
   }) %>%
   sort() -> seats
 

js/05.js

@@ -2,40 +2,30 @@ var fs = require("fs")
 
 input = fs.readFileSync("../input/05-01.txt", "utf-8")
 
-res = input
-  .split("\n")
-  .filter((x) => x.length > 1)
-  .map((line) => {
-
-    lb = 0
-    ub = 127
-
-    for (part of line.substr(0, 7)) {
-      amt = Math.floor((ub - lb)/2) + 1
-      if (part === "F") {
-        ub -= amt
-      } else {
-        lb += amt
-      }
+partition = function(seq, lb, ub, trigger) {
+
+  for (part of seq) {
+    amt = Math.floor((ub - lb)/2) + 1
+    if (part === trigger) {
+      ub -= amt
+    } else {
+      lb += amt
     }
+  }
 
-    row = (line.charAt(6) === "F") ? lb : ub
+  return((seq.slice(-1) === trigger) ? ub : lb)
 
-    lb = 0
-    ub = 7
+}
 
-    for (part of line.substr(7, 3)) {
-      amt = Math.floor((ub - lb)/2) + 1
-      if (part === "L") {
-        ub -= amt
-      } else {
-        lb += amt
-      }
-    }
-
-    seat = (line.charAt(9) === "R") ? lb : ub
+res = input
+  .split("\n")
+  .filter((x) => x.length > 1)
+  .map((line) => {
 
-    return((row * 8) + seat)
+    return(
+      (partition(line.substr(0, 7), 0, 127, "F") * 8) +
+      partition(line.substr(7, 3), 0, 7, "L")
+    )
 
   }).sort()